Algorithm finds when a zigzag path is the quickest

A zigzag path can be quicker than a straight line when travelling underwater, due to constantly changing currents that can both help and hinder progress. Now, researchers have figured out an algorithm that lets automated underwater vehicles (AUVs) navigate turbulent waters in the most efficient way possible.

Swarms of underwater drones are often used for mapping and oceanographic research but Pierre Lermusiaux, a mechanical engineer at MIT who led the research, says previous attempts at planning an optimal path through changing currents weren't accurate enough or required too much computational power.

The algorithm can find the path with the shortest travel time between two points or with the minimum use of energy and it can also find paths that maximise the collection of important data. The resulting paths often loop back on themselves, as it can be quicker to follow the current in one direction and then double-back, rather than fighting to cut across.

While the algorithm was developed with underwater vehicles in mind, Lermusiaux says it could also be used by aerial drones struggling against the winds or even by tiny medical robots designed to swim through blood vessels. The team will present their research at the International Conference on Robotics and Automation in St. Paul, Minnesota this May.